Aeroplane



Dec. 3, 1935. MARMQNIER 2,023,334 I AEROPLANE Filed March 2, 1932Patented Dec. 3, 1935 AEROPLANE Louis Marmonier, Lyon, FranceApplication March 2,

In France March 10, 1931 Claims.

The purpose of the present invention is the application oi tiltingpropellers to aeroplanes of the ordinary type so that they can beutilized either as propellers to drive the aeroplane and maintain 5 itsrelative speed, or simultaneously as driving and supporting propellersin order to support the aeroplane during its descent, to facilitatelanding or to enable it to rise without the necessity of setting theaeroplane at a dangerous angle of approach. The device is therefore acompromise between the ordinary aeroplane and the helicopter, since itutilizes the respective properties of each of these machines.

The presence, however, of tilting propellers on an aeroplane presentstwo distinct problems-a gyroscopic problem and an aerodynamic problem.The conditions under which these propellers are employed are not thesame as those of an aeroplane of the present type where they are placedin a fixed position, and where their tractive effort is exercised alwaysin the same direction and at the same point of theaeroplane.

When the aeroplane is in the line of flight the tilting propellers areplaced in their normal position, their driving force being exercisedexclusivcZy in the direction of flight of the machine and withoutlimitation of speed resulting from supplementary apparatus as is thecase with helicopters or those of the type known as autogiral. In orderto cause the aeroplane to rise or descend, the propellers are set moreor less towards the zenith in order that their tractive effort maycontribute not only towards the maintenance by the wings of all theircarrying power but to increase the support of the aeroplane in aproportion corresponding to their inclination from the zenith and totheir speed of rotation.

To modify the angle of the propellers in relation to the supportingplanes of the aeroplane, several methods can be employed. That whichappears to be the most simple and the easiest to fit to aeroplanesconsists in tilting the motor unit together with its propeller, the axisof rotation being arranged so that their masses are balanced.

To prevent these tilting propellers, which constitute powerfulgyroscopes, from afiecting the lateral and longitudinal stability of theaeroplane when they are tilted, theyare-and these are the principalcharacteristics of the invention- 1. Coupled in pairs and rotate-atequal speeds but in opposite directions to one another;

2. For each pair, mounted so as to pivot on a rigid frame, and arejoined by an appropriate device so that they tilt simultaneously underthe action of a single force.

1932, Serial No. 596,32

Further, these propellers, which can be mounted in line one behind theother are staggered, are so placed in the aeroplane that their centre oftractive'eiiort passes through the centre of gravity or on theperpendicular of the centre of grav- 5 ity of the machine and that thiscentre of gravity is itself on the longitudinal axis of the buoyancycentres of the supporting wings of the aeroplane which are placed in thesame plane and connected by fuselages.

The invention will be quite clear from the supplementary descriptionwhich follows and from the attached drawing, which are of course givenespecially as explanatory documents.

Figure 1 shows a diagrammatic-view of a gyroscope mounted on a rigidframe, in unstable equilibrium, and under the action of the tiltingforce.

Figure 2 represents two gyroscopes with the same inertia, rotating inopposite directions and mounted on a rigid frame, and in unstable equi-20 librium, these gyroscopes being connected together by a coupling andsubjected to the action of the same tilting couple.

Figure 3 represents the same arrangement as the above, the gyroscopesbeing in a different position and subjected to the action of a singlechecking force.

Figure 4 shows a small type helicopter aeroplane with two tiltingpropellers to which the arrangement is adapted. 30

Figure 5 shows the height control applied to the helicopter aeroplaneand consisting of two compensated planes which balance one another.

In Figure 1, the gyroscope a is actuated by a motor mounted in a cradleI. This cradle pivots on a frame 2, which is in a state of unstableequilibrium. This gyroscope rotates in the direction of the arrow 3 andcan be tilted in its frame by the action of lever 4. If this lever canproduce a force 5, assuming that this force has a 40 point ofapplication, the point m of the gyroscope it being acted on by force mmoves to m" in consequence of its rotation in the direction. of thearrow 3. The frame 2 then pivots in the direction of the arrows 6 and 'landtilts in the direction of the arrows 8 and 9 under the influence ofthe force 5.

Consequently, an aeroplane provided with only one tilting propeller,would exert not only a very appreciable tilting force; since this wouldhave to overcome all of its gyroscopic inertia, but, owing to thistilting, the aeroplane would be liable to slip and its longitudinalequilibrium would be endangered.

In Figure 2,

which represents two gyroscopes coupled together and rotating inopposite directions, gyroscope b in the direction of arrow I andgyroscope 0 towards arrow ll, these gyroscopes are tilted under totallydifferent conditions, provided that the tilting is caused by one and thesame couple and has exactly the same amplitude. To do this, the twogyroscopes b and c are both actuated by lever l2 through a mechanicalconnection 32, so that their planes of rotation remain always parallel.When the couple I3 is produced by this lever, the point 11. of gyroscopeb is caused to move to n, which would cause the rigid frame It to pivotin the direction of the arrows l5 and I6, if the gyroscope 0 did notreact in the opposite direction towards arrows I1 and I8, for the point0 moves to 0'. These precession couples act in opposite directions,their value being equalized. Since they are produced simultaneously on arigid frame, they oppose one another in this frame and in the connectionbetween the gyroscopes. The respective inertias of the two gyroscopestherefore annul one another.

Figure 3 illustrates the same arrangement as Figure 2, the gyroscopes band 0 being in a different position after tilting. To move them back totheir original position lever I2 is moved in the direction of arrow l9producing on the gyroscope b a precession couple 2!! and 2| to which isopposed a couple 22 and 23 of the same value and caused by gyroscope 0.These couples annul one another in the rigid frame l4 and the forcerequired to carry out this operation is practically nil From thisexplanation, it will be evident that when two tilting propellers coupledtogether by a connection which makes them act together and maintaintheir parallel planes of rotation, are fitted to an aeroplane, if thesepropellers rotate in opposite directions at the same speed, relativelyno force is required to tilt them and this can be done by the pilot by asingle operation.

On the basis of this very interesting property, the helicopter aeroplanerepresented in Figure 4 has been developed, the same arrangements beingapplicable to large machines with multiple propellers coupled in pairs.In this machine the two tilting propellers 24 and 25 rotate in oppositedirections as shown by arrows 23 and 21, their speeds being equal, asnearly as possible, to facilitate the tilting. In the case shown in thedrawing the propellers are situated in line on the aeroplane; they couldequally well be staggered. When the aeroplane is in its line of flightthe tilting propellers are in their normal position as drivingpropellers. They tilt in the direction of the arrows Z8 and 29 to givesupport to the aeroplane during ascent and descent and also in case ofloss of speed.

The engines which drive the propellers and tilt with them are mounted inthe cradles 30 and 3| which can pivot. These cradles, which consist ofwelded tubing or of light channel-steel, turn in bearings mounted on thetwocarlings of the aeroplane. Their shafts are carefully balanced sothat the weight of the engine counterbalances that of the propeller.These two cradles are coupled together by mechanical means, that shownin the drawing being merely typical. This can be modified to suit theaeroplane and the arrangement of the propellers. The connection inFigure 4 comprises: two levers mounted on the cradle shafts 30 and 3|,these levers being coupled together by the rod 32 which couples togetherthe two propellers 24 and 25,

The propellers are tilted by a pedal 33 operated by the pilot throughthe shaft 34 and rod 35, their return to the driving position beingeffected by spring 36. This pedal control can, if desired, be assistedby a vacuum servo-motor operated by 5 the foot pedal and mounted on oneof the propeller engines, this servo-motor being similar to those usedfor motor-car brakes. Compressed air would be employed in the case oflarge aeroplanes or when an automatic stabilizer is fitted.

The handle 31, in addition to operating the compensated and balancedheight controls 38 and 39 and the adjustment of the wings, also servesin known manner to control the direction of the aeroplane.

These various operations could equally well be carried out by anautomatic stabilizer.

On the other hand, the tractive centre of the propellers passes throughthe centre of gravity G of the machine so that the actual wing supportwill not be afiected by the change in direction of propulsion of thepropellers. The centre of gravity of the aeroplane lies on thelongitudinal axis of the buoyancy centres of the supporting wings.

Moreover, the profile of the propeller blades is such that they can actsimultaneously for driving and supporting. This arrangement could alsobe applied in all cases in conjunction with a speed-loss indicator andvane for registering side winds.

Another characteristic of this helicopter aeroplane consists in thepositions in the aeroplane of the pilot and the passengers, who areplaced at the back for increased safety. In this position they areisolated from the engines, propellers, and from the petrol tanks, etc.The supervision of the. machine and correction of the flight in relationto the horizon are facilitated and landing is rendered easier since thepilot, being able 40 to see the track, can manoeuvre correctly.Furthermore, this arrangement makes it possible to fit an automaticparachute 40 on the aeroplane which is caused to open outinstantaneously by the speed of the aeroplane. Also this can in case ofaccident he used, even at the last minute.

On the other hand. this helicopter-aeroplane being auto-stable by itsconstruction, in consequence of the large distance between thesupporting wings, the longitudinal governor will necessitate planes oflarge dimensions so that the adjustment of the aeroplane may beinstantaneous. This operation is difficult for the pilot and to reducethe force required for it the height control consists of movable planesof which one 39 is 5 mounted in front of the aeroplane on the front ofthe wing and the others 38 at the back. These planes, connected to thehandle 31 by rods 4| and 42, are compensated and balance one another.When the pilot operates the handle 31 in order to direct his machine, hemust overcome the couple p which is caused by the resistance of the aircurrents on plane 38 which make the couple 9. 0n the other hand, thiscouple will be compensated by couple q resulting from couple q acting onplane 33. It will then be possible to fit to the helicopter-aeroplaneplanes sufiiciently large to allow the height control to act.

The landing speed of the helicopter-aeroplane can be increased while inflight and so increase the sensitiveness of the machine.

What I claim and desire to secure by Letters Patent of the United Statesis:-

1. A helicopter aeroplane having transversely extending front and rearsupporting planes, (5

longitudinally extending frame members located at opposite sides of theaeroplane and connecting the front and rear supporting planes and spacedapart to provide a central propeller receiving space open throughout theentire length of said frame members, a pair of tiltable propellersarranged in tandem within said central open space and havingcounterbalancing motors, propeller and-motor supporting means comprisingtrans-- verse cradles journaied at their ends on the frame members andconstituting transverse axes to permit pivotal movement of thepropellers and their motors, and means for coupling the cradles forsimultaneously tilting the propellers and motors on their transverseaxes to arrange the propellers in either their horizontal or verticalpositions.

2. A helicopter aeroplane having transversely extending front and rearsupporting planes, longitudinally extending frame members located atopposite sides of the aeroplane and connecting the front and rearsupporting planesand spaced apart to provide a central propellerreceiving space open throughout the entire length of said frame members,a pair of tiltable propellers arranged in tandem within said centralopen space and having counterbalancing motors, propeller and motorsupporting means comprising transverse cradles journaled at their endson the frame members and constituting transverse axes to permit pivotalmovement of the propellers and their motors, and means for coupling thecradles for simultaneously tilting the propellers and motors on theirtransverse axes to arrange the propellers in either their horizontal orvertical posi-' tions, said propellers being rotatable in oppositedirections so as to balance their gyroscopic effects during the tiltingoperation.

3. A helicopter aeroplane having transversely extending front and rearsupporting planes,

longitudinally extending frame members located at opposite sides of theaeroplane and connecting the front and rear supporting planes and spacedapart to provide a central propeller receiving space open throughout theentire length of said frame members, a pair of tiltable propellersarranged in tandem within said central open space and havingcounterbalancing motors, propeller andmotor supporting means comprisingtransverse cradles journaled at their ends on the frame members andconstituting transverse axes to permit pivotal movement of thepropellers and their motors, the propellers being rotatable in oppositedirections with thefront propeller located in front of its pivotal axiswhen in a vertical position and the rear propeller located in rear ofits pivotal axis when in its vertical position, and means for couplingthe propellers and for simultaneously swinging the same about their axeswhereby when the propellers are moved to a horizontal position, thefront propeller will be located above its pivotal axis and the rearpropeller will be located below its pivotal axis, thereby balancingtheir gyroscopic effects during the tilting operation.

4. A helicopter aeroplane having transversely extending front and rearsupporting planes, longitudinally extending frame members located atopposite sides of the aeroplane and connecting the front and rearsupporting planes and spaced apart to provide a central propellerreceiving space open throughout the entire length of said frame members,a pair of tiltable propellers arranged in tandem within said centralopen space and having counterbalancing motors, propeller and motorsupporting means comprising transverse cradles journaled at their endson the frame members and constituting transverse axes to permit pivotalmovement of the propellers and their motors, the propellers beingrotatable in opposite directions with one propeller located in front ofits pivotal axis when in a vertical position and the other propellerlocated in rear of its pivotal axis when in its vertical position, andmeans for coupling the propellers and for simultaneously swinging thesame about their axes whereby when the propellers are moved to ahorizontal position, the first propeller will be located above itspivotal axis and the second propeller will be located below its pivotalaxis, thereby balancing their gyroscopic effects during the tiltingoperation. a

5. A helicopter aeroplane having transversely extending front and rearsupporting planes, longitudinally extending frame members located atopposite sides of the aeroplane and connecting the front and rearsupporting planes and spaced apart to provide a central propellerreceiving space. open throughout the entire length of said framemembers, a pair of tiltable propellers ar-' ranged in tandem within saidcentral open space along the longitudinal axis of the aeroplane andhaving their center of traction at the center of gravity of theaeroplane and having counterbalancing motors, propeller and motorsupporting means comprising transverse cradles journaled at their endson the frame members and constituting transverse axes to permit pivotalmovement of the propellers and their means for coupling the cradles forsimultaneous- 1y tilting the propellers and motors on their transverseaxes, to arrange the propellers in either their horizontal or verticalpositions, said propellers being rotatable in opposite directions so asto balance their gyroscopic effects during the tilting operation.

LOUIS MARMONIER.

motors, and I

